1. Field of the Invention
The present invention relates to an easily releasable terminal structure that allows the terminals of a plurality of storage batteries to be releasably connected. More particularly, the present invention is directed to a storage battery terminal structure adapted for connecting and disconnecting storage batteries for electric vehicles.
2. Related Art
Various types of storage battery terminal structures have heretofore been known. For example, a storage battery terminal structure such as shown in FIG. 16 has been proposed. FIG. 16 is an exploded perspective view showing an example of a conventional storage battery terminal structure.
In FIG. 16, a conventional storage battery terminal structure 101 includes: a male terminal 103 that is erected on the upper surface of a storage battery main body 102; and a female terminal 104 having a male terminal insertion hole 105 engageable with the male terminal 103 and a crimping portion 106 for connecting a wire W by crimping.
More specifically, an opening 107 is arranged on an end of the male terminal insertion hole 105, and a pair of projecting portions 108 are formed on both sides of the opening 107. These projecting portions 108 extend from an end of an electric contact portion 109 surrounding the male terminal insertion hole 105. Further, in order to reduce the inner diameter of the male terminal insertion hole 105 by tightening the pair of projecting portions 108 with a bolt 110 and a nut 111, through holes 112 for inserting the bolt 110 are arranged in the projecting portions 198. Further, in order to prevent excessive tightening of the bolt 110 and in order to provide an appropriate degree of tension, an L-shaped metal piece 115 formed of a washer portion 113 and a stopper portion 114 having a projecting height H is arranged.
In the thus constructed conventional storage battery terminal structure 101, the male terminal 103 is electrically connected to the male terminal insertion holed 105 in the following way. The male terminal insertion hole 105 of the electric contact portion 109 is inserted into the male terminal 103 that is usually called a "battery post". Then, the bolt 110 is inserted into the washer portion 113 and the through holes 112, and is thereafter tightened up by the nut 111. As a result, when the nut 111 comes in contact with the stopper portion 114, the male terminal insertion hole 105 tightens up the male terminal 103 with an appropriate degree of tension without pressure loss, and thus the male terminal 103 is electrically connected to the male terminal insertion hole 105 reliably.
However, in the aforementioned conventional storage battery terminal structure 101, a tightening tool must be used in order to tighten the bolt 110 and the nut 111 up. Therefore, if, for example, storage batteries are placed close to each other as in an electric vehicle or the like and the place where the storage batteries are put is so narrow as to leave only a small distance between the terminals of the batteries, there exists a problem that the tightening tool interferes with parts such as the electric contact portion 109 and the like of the adjacent storage batteries. As a result, the tightening operation becomes hard and operation efficiency is impaired.
Further, even if the storage battery terminal structure 101 is tightened up with the bolt 110 and the nut 111, whether or not the storage battery terminal structure 101 has been connected to the male terminal 103 completely cannot be checked visibly with ease, which has made the operation very inconvenient.
Still further, when the storage battery terminal structure 101 is applied to electric vehicles that employ high-voltage storage batteries, the operator is likely to touch the storage batteries directly with his hand, which has made the operation dangerous.